William Donaldson, chairman of the Securities and Exchange Commission, has said little publicly about his plans, but he has made it clear they will be shaped by his strong views in two divisive debates, the Wall Street Journal said.

One is that the last decade's proliferation of new electronic stock markets has created a jumble that hurts investors. A pioneer on Wall Street and longtime champion of free markets, Donaldson wants to regulate the fragmented market that has sprung up in stock exchanges.

Donaldson is also wrestling with a fundamental dispute that goes to the very core of how stocks are bought and sold: What's more important -- the best price or the most speed? He leans toward wanting investors always to get the best price, though he recognizes that speed is also important to many investors.